Ion
Exchange
http://en.wikipedia.org/wiki/Groundwater_remediation
http://www.wqpmag.com/new-technology-groundwater-remediation
Ion exchange for ground water remediation is
virtually always carried out by passing the water downward under pressure
through a fixed bed of granular medium (either cation exchange media and anion
exchange media) or spherical beads.
Ions
are negatively or positively charged atoms or molecules. Ion exchange resins
have the opposite charge of the contaminant ions they are treating. This causes
the contaminants to be attracted to and stick to the ion exchange resin similar
to the way metal reacts to a magnet. When the contaminant ion attaches to the
resin, it displaces another similarly charged ion into the water being treated.
That ion is “exchanged” for the contaminant.
Ion
exchange is an exchange of ions
between two electrolytes or between an electrolyte and a complex. In most
cases, the term is used to denote the process of purification, separation and
decontamination of aques and other ion containing solution with solid polymeric
ion exchangers.
Typical ion exchangers are ion exchange resins(porous or gel polymer (functionalized
porous or gel polymer), zeolites,
montmoriollonite, clay and soil humus. Ion exchangers are either cation
exchangers that exchange positively charged ions or anion exchangers that
exchange negatively charged zeolites, montmorillonite, clay and soil humus.
Ion exchangers are either cation exchangers that exchange positively chaged ions
or anion exchangers that exchange negatively charged ions. There are also amphoteric exchangers that are able to exchange both cations
and anions simultaneously. However, the simultaneous exchange of cations and
anions can be more efficiently performed in mixed
beds that contain a mixture
of anion and cation exchange resins, or passing the treated solution through
several different ion exchange materials.